A technique for performing three-dimensional measurement by use of a non-prism type total station (surveying instrument), which does not use a reflection member such as a corner cube, has been developed.
However, the problem to be solved was that, for example, when the outward appearance of a building is measured, it was extremely difficult to measure the edges (corners) of the building. Because the measurement is performed by use of a measuring light beam such as a laser light beam which is emitted from a non-prism type total station (surveying instrument), it is difficult to measure the edge.